diff --git a/drivers/bios_emulator/Makefile b/drivers/bios_emulator/Makefile
index 330f36f..e56356e 100644
--- a/drivers/bios_emulator/Makefile
+++ b/drivers/bios_emulator/Makefile
@@ -8,8 +8,5 @@
 	$(X86DIR)/sys.o \
 	$(X86DIR)/debug.o
 
-EXTRA_CFLAGS += -I$(srctree)/$(src) -I$(srctree)/$(src)/include \
+ccflags-y := -I$(srctree)/$(src) -I$(srctree)/$(src)/include \
 	-D__PPC__  -D__BIG_ENDIAN__
-
-CFLAGS += $(EXTRA_CFLAGS)
-CPPFLAGS += $(EXTRA_CFLAGS)